The first extensive medical examinations of former detainees in U.S. military jails offer corroboration for prisoners' claims of physical and psychological abuse at the hands of their American captors, a Boston-based human rights group said in a report released yesterday.

The assessments of 11 men formerly held in U.S. detention camps overseas revealed scars and other injuries consistent with their accounts of beatings, electric shocks, shackling and, in at least one case, sodomy, according to the report by Physicians for Human Rights. Most also had symptoms of long-term psychological damage, including post-traumatic stress disorder, the group said.

The physicians' group, which in recent years has been critical of the administration's detention policies, arranged for a battery of exams for 11 former detainees who had spent an average of three years in detention at U.S. facilities in Iraq, Afghanistan or Guantanamo Bay, Cuba. Teams of medical specialists conducted physical and psychological tests, including exams intended to assess if the subjects were lying.

The evaluations backed up the men's stories of physical and sexual assault and documented psychological damage that had left many of them severely impaired, the report said. For example, exams and X-rays of one of the former detainees showed scars and joint injuries that supported his description of being suspended for hours by his arms at the Abu Ghraib prison in Iraq.

All 11 men were eventually released from custody without being charged with crimes.

In a statement accompanying the report, retired Maj. Gen. Antonio M. Taguba, who led the Army's first official investigation on Abu Ghraib, said the new evidence suggested a "systematic regime of torture" inside U.S.-run detention camps.

A Pentagon spokesman yesterday criticized the report, saying its authors had drawn "sweeping conclusions based upon dubious allegations" of former detainees who had been out of U.S. custody for years.

"The quality of medical care we provide detainees is similar to that which our troops serving in the same locations receive," said the spokesman, Navy Cmdr. J.D. Gordon. "We have robust psychological and mental health care available to detainees."